Femto cells—building-based wireless access points interfaced with a wired broadband network—are generally deployed to improve indoor wireless coverage and to offload a mobility radio access network (RAN) operated by a wireless network and service provider. Femto cells typically operate in licensed portions of the electromagnetic spectrum, and generally offer plug-and-play installation; e.g., automatic configuration of femto access point. Improved indoor coverage includes stronger signal and improved reception (e.g., voice or data), ease of session or call initiation, and session or call retention as well. Offloading a RAN reduces operational and transport costs for a service provider since a lesser number of end users utilizes over-the-air (OTA) radio resources (e.g., radio frequency bands and channels), which are typically limited.
Coverage of a femto cell, or femto access point (AP), is generally intended to be confined within the bounds of an indoor compound (e.g., a residential or commercial building) in order to mitigate interference among mobile stations covered by a macro cell and terminals covered by the femto AP. Additionally, confined coverage can reduce cross-talk among terminals serviced by disparate, neighboring femto cells as well. Femto cells typically operate in licensed portions of the electromagnetic spectrum, and generally offer plug-and-play installation; e.g., automatic configuration of femto AP subsequent to femto cell subscriber registration with a service provider. Coverage improvements via femto cells can also mitigate customer attrition as long as a favorable subscriber perception regarding voice coverage and other data services with substantive delay sensitivity, or otherwise, is attained. In addition, a richer variety of wireless voice and data services can be offered to customers via a femto cell since such service offerings do not rely primarily on mobility RAN resources.
To ensure an improved perception of wireless service via femto coverage, access control has to be minimally disruptive in connection with preservation of mobile device battery life. Access control is one of the base requirements for femto cell network operation. Each femto access point (AP) and macro cell sector broadcast a specific, yet not always unique location are code (LAC); non-uniqueness of LAC typically is reflected in LAC reuse throughout a macro sectors and femto APs deployments. Generally, subscriber station looks for changes in received LAC prior to attempting to attach to new macro or femto sectors, or access points. In response to attachment signaling, a femto cell AP must allow or disallow subscriber stations to attach, camp and place calls. To that end, femto APs can utilize the status (e.g., allowed or disallowed) of the subscriber station within a specific access lists associated with respective femto APs. If disallowed, the subscriber station is to be rejected in such a way as to allow normal service on the macro network or emergency-only service on the femto AP.
While various legacy rejection mechanisms are available, legacy LAC planning for macro network and access control mechanisms do not optimize LAC reuse to minimize utilization of rejection techniques that can recurrently reject subscriber stations that, in view of mobility aspects, recurrently attempt attachment with femto APs that do not allow the subscriber station to attach. Instead typical legacy mechanisms plan LAC according to interference measurements or reuse distance. Such planning can fail to address real-world mobility situations associated with subscribers of macro and femto networks as the subscriber routinely travel. Such failure may result in optimal access control to macro and femto coverage with suboptimal battery life, with ensuing detriment to subscriber perceived experience.